3.2.3. Soil Conservation Service

From 2000 to 2018, soil conservation service supply exceeded the demand, and both showed an increasing trend (Table 2). The surplus of soil conservation services increased significantly from 3.52 billion tons in 2000 to 5.6 billion tons in 2010 and 4.67 billion tons in 2018. Soil conservation services, as an in-situ service, i.e., one that is generated in situ and benefits in situ, have an aggregate surplus that hardly offsets their spatial mismatch.

In terms of the spatial distribution of the soil conservation services ESDR, the deficit areas were concentrated in the north-central region of the study area and the downtown area in the east (Figure 4). The spatial mismatch in soil conservation services was mainly due to: (1) the north-central region being a loess plateau area, which is very weak for soil and water conservation due to the undulating terrain, loose soil, and poor vegetation cover; (2) the eastern city center area, with strong human activity and high population density in the area, which has led to a reduction in vegetation area. The land-use types are mainly urban land, rural settlements, and other construction lands, which have a poor soil conservation capacity, thus leading to a deficit in soil conservation services.

## 3.2.4. Grain Production Service

Grain production service increased from 125.54 million tons in 2000 to 214.51 million tons in 2018, an increase of 70.87%. During the same period, grain production demand exhibited an increase of 14.24% from 51.30 million tons in 2000 to 58.62 million tons in 2018 (Table 2). Thus, there was a clear surplus for grain production service, and this surplus showed an increasing trend, from 74.23 million tons in 2000 to 155.90 million tons in 2018.

Despite the overall surplus in grain production service, there were still some spatially mismatched centers (Figure 5). The southeastern part of the study area has relatively good hydrothermal conditions and is a major grain producer, hence the high grain supply. At the same time, the grain demand was relatively high due to the high level of human activity and the relatively high population density in the area. The region's grain production service showed a surplus, indicating that its production capacity was greater than its consumption capacity.
